Google is testing adding a rainbow effect to the AI Mode and Web tabs within the search bar. We've seen this on the AI Mode button on the search box and it seems Google is testing it to highlight some of the tabs.
I can replicate this for the AI Mode tab, here is my video:
I was able to replicate it once for the web tab, but here is Brodie Clark's video of it which he posted on X:
Brodie wrote, "As part of the new Web Guide experience in labs that you can opt in to, Google is now bringing attention to the 'Web' tab with the rainbow effect. This effect would previously only show for the AI Mode tab."
I do wonder if this should have been reserved for the AI Mode tab and it showing on the web tab is a bug.
Forum discussion at X.
